John Panuska Natural Resources Extension Specialist Biological Systems Engineering Department UW – Madison Wisconsin Crop Management Conference January 16, 2014

Focus Topics for Today -Methods for monitoring liquid dairy manure dry matter content. -What does dairy manure dry matter say about total phosphorus content for WI manures ?

So why do you want to know manure dry matter content ? - Better manage injected manure / nutrient loss risk through sub-surface tile drains Field observations suggest reduced tile loss risk for dry matter content greater than 5%, Gibbs (2013). - Some studies suggest you can estimate manure total phosphorus content from dry matter content.

Pressurized flow via preferential pathways - Biopores - Structural cracks Dyed Burrow Source: M. Shipitalo, USDA - ARS How manure gets into tiles..

Manure flow through tiles

Monitoring Liquid Dairy Manure Dry Matter Content Laboratory Method – the gold standard, takes time. Recommended Methods of Manure Analysis UWEX Publication No. A3769, Edited by John Peters. Available at: learningstore.uwes.edu. Essentially weighing, drying and weighing again. High quality control.

Monitoring Liquid Dairy Manure Dry Matter Content Quick Methods are simple, quick & inexpensive and may be accurate enough. Quick methods should be used along with laboratory methods and NOT in place of laboratory methods

Monitoring Liquid Dairy Manure Dry Matter Content Quick Methods Advantages Simple, quick and inexpensive Equipment is easy to obtain and operate Provides reasonably accurate result for the same manure type and source Disadvantages Less accurate and precise than laboratory methods Needs calibration for manure type and source Can be impacted by local conditions (ex. climate, operator skill level, variations in method)

Monitoring Liquid Dairy Manure Dry Matter Content  UW – BSE In-Field Liquid Dairy Manure Solids Tester  Hydrometer Method

Monitoring Liquid Dairy Manure Dry Matter Content Hydrometer Method The hydrometer test method for estimating P content of liquid manure is based on the tendency for manure P to associate with the solids. The method has been used successfully in the Mammoth Cave area of Kentucky. Coefficient of determination (R 2 ) for hydrometer quick test for several farms in the Mammoth Cave area, KY. ParameterR 2 Total Solids 0.76 – 0.81 Total P 0.93 Source: Bicudo, 1991

Monitoring Liquid Dairy Manure Dry Matter Content UW – BSE In-Field Liquid Dairy Manure Solids Tester - Designed and prototype built for a BSE Senior Design Capstone class project. - The initial prototype was further evaluated using additional farms with digested manure solids bedding.

The funnel (8) connects to a mesh filter screen (2) and a final collection system (10) captures effluent passing through the screen. The Tester Explained

The 400 ml (13.5 oz.) sample is held in the funnel by a flap valve that when released drops the sample onto a 2” Dia. - 9/16” long x 3/16” wide diamond shaped screen. The Tester Explained Read retained volume here

Laboratory Test Results Replicated sample testing gives a coefficient of variation in TS content of about 1- 2% at the 5% TS level

All WI Farms over 12 years, n=6,100 Data source: UW Soil Plant Analysis Lab

All WI Farms over 12 years, n=6,100 Data source: UW Soil Plant Analysis Lab

One Farm Over 15 Months; n=150 Data source: UW Soil Plant Analysis Lab

One Farm Over 15 Months; n=150 Data source: UW Soil Plant Analysis Lab

1.Wisconsin data from multiple farms do not indicate a meaningful relationship between percent TS and pounds TP per 1000 gallons of manure liquid or slurry. 2.Wisconsin data from a single farm do not indicate a meaningful relationship between percent TS and pounds TP per 1000 gallons of manure liquid or slurry. 3.The manure quick test device developed by BSE students appears to be able to adequately distinguish between dairy manure with 6% dry matter solids content when tested with digested solids bedding. Conclusions

Bicudo, J. R Managing liquid dairy manure. University of Kentucky Cooperative Extension Service, Publ. No. AEN p. Gibbs, F. dated January 10, REFERENCES